1. Field of the Invention
The present general inventive concept relates to an image processing apparatus. More particularly, the present general inventive concept relates to an image processing apparatus capable of differently setting a clock ratio according to a use rate of a CPU (central processing unit), and a control method thereof.
2. Description of the Related Art
In general, an image processing apparatus includes a printer, a facsimile, a multi-function peripheral, and a duplicator and has a function of printing a document or an image. Such an image processing apparatus includes a printing engine that prints a document or an image on a recording medium, a CPU that controls the printing engine, and a system bus that transmits results processed by the CPU to the printing engine or other peripheral devices.
In order to improve the performance of an image processing apparatus, the performance of a CPU must be enhanced. In order to improve the performance of the CPU, the process speed of the CPU must be increased by increasing an operation speed (hereinafter, referred to as the CPU clock frequency).
However, as the CPU clock frequency is increased, other peripheral devices may not keep pace with the high CPU clock frequency and thus a system may not normally operate. If the CPU clock frequency is too high in a micro circuit, various types of radio noises may be generated in a circuit board and other peripheral devices may be subject to such radio noises. Accordingly, a clock ratio has been used in order to keep pace with a high clock frequency, such as the CPU clock frequency, and a low clock frequency such as a bus clock frequency.
A clock ratio denotes a ratio of a CPU clock frequency to a bus clock frequency. When a conventional image processing apparatus using such a clock ratio is powered on, the image processing apparatus operates by using a predetermined CPU clock frequency and a predetermined bus clock frequency.
When a document or an image is printed using the conventional image processing apparatus, the printing operation may be subject to a CPU clock frequency or a bus clock frequency according to the type and characteristics of emulation (that is, a printer control program) in accordance with a print command transmitted from a printer driver. For example, when software processing is performed by a CPU core, increasing the CPU clock frequency is advantageous for improving the printing performance. When a rendering operation is performed by emulation using many hardware accelerators, increasing the bus clock frequency is advantageous for improving the printing performance.
However, since the conventional image processing apparatus operates by using a predetermined CPU clock frequency and a predetermined bus clock frequency without considering the type and characteristics of emulation, the energy efficiency may be degraded and the performance of the conventional image processing apparatus may deteriorate.
Thus, the conventional image processing apparatus may not be efficiently operated.